UNIVERSITY OF ILLINOIS AT CHICAGO
Department of Psychiatry
Fifth Annual Research Forum – Extravaganza 2014
POSTER TITLE
BOLD fMRI and ERP Measures Of Socio-Emotional Brain Function In CombatRelated PTSD
DISEASE/KEY
WORDS:
Posttraumatic stress disorder, PTSD, event-related potentials, faces, affect, late
positive potential, LPP, amygdala
AUTHORS:
Annmarie MacNamara, Daniel A. Fitzgerald, Christine A. Rabinak, Amy E. Kennedy &
K. Luan Phan
MENTEE
CATEGORY:
Post-doctoral Fellow
BACKGROUND:
Functional magnetic resonance imaging (fMRI) of blood-oxygenation level-dependent
(BOLD) signals and electroencephalographic (EEG) event-related potentials (ERPs) are
complimentary approaches that optimize spatial and temporal resolution,
respectively, to examine the neural correlates of emotional reactivity. However,
because relationships between ERP and BOLD measures are poorly understood,
synthesis of these findings is limited. To resolve this, recent work has examined
correspondence between BOLD-fMRI and ERP measures in healthy individuals; few
studies have jointly examined fMRI and ERP indices of emotion in clinical
populations. Patients with posttraumatic stress disorder (PTSD), a disorder of
abnormal threat perception and affect dysregulation, exhibit aberrant prefrontal and
amygdala reactivity as well as blunted late positive potentials (LPP) ERPs in tasks
involving socio-emotional information processing; however, no study to-date has
combined BOLD and ERP in the same individuals with PTSD.
Male veterans returning from military combat in Operations Enduring Freedom and
Iraqi Freedom (OEF/OIF) - 36 with PTSD and 29 without PTSD - performed a wellvalidated emotional faces and geometric shapes matching task during separate EEG
and fMRI BOLD recording sessions. We used temporal spatial principal component
analysis (PCA) to isolate components underlying the ERP waveform in response to
emotional faces (> shapes) and then used these components as subject-specific
regressors in a whole-brain analysis of BOLD activity.
Across participants, emotional faces elicited fMRI BOLD activation consistent with an
‘emotion’ brain network as well as enhanced LPPs. Four PCA factors differentiated
faces > shapes; we focused our analysis on an early-onset occipital factor consistent
with the LPP. Across all participants, LPP enhancement to emotional faces
corresponded to modulation of BOLD activity in the amygdala, insula, visual cortex
and fusiform gyrus.
Fusing BOLD fMRI and ERPs avails novel hypotheses about the neural generators of
the LPP that could be tested in future investigations, particularly those that measure
BOLD and ERP simultaneously.
METHODS:
RESULTS:
CONCLUSIONS:
RESEARCH MENTOR:
K. Luan Phan